FormatFlow

No tool matches “”

Try a format (“webp”, “mp3”) or a verb (“merge”, “compress”).

PDF toolsImage toolsVideo toolsAll tools

Loading index

↵to open

Image Tools · Updated October 20, 2026

Base64 to Image Decoder

You can paste a Base64 string or data URL and decode it back into a viewable image in your browser, with automatic format detection, a preview and a one-click download without uploading anything.

Runs in your browserFree · No sign-up · No watermark
BASE64 → IMAGERuns in your browser
Loading the tool…

Everything runs locally in this tab. No file is uploaded while the tool loads.

This tool runs in your tab. Nothing is uploaded and no copy is stored.

How files are handled

At a glance

Works with
BASE64 → IMAGE
Processing
In your browser
Max size
Up to about 40 MB of Base64 text
Price
Free, no account
Updated
October 20, 2026
All Image Tools

About Base64 to Image

Base64 image strings arrive from APIs, database exports, email templates and configuration files, and reading them as text tells you very little. Pasting one here decodes it into real image bytes, shows a preview and lets you save the file with the correct extension. The decoder sniffs the PNG, JPEG, GIF, WebP, BMP or SVG signature, so a raw payload without a data URL prefix still works.

The tool also handles the annoying variations: whitespace and line breaks from wrapped logs, the URL-safe alphabet that swaps + and / for - and _, and percent-encoded data URLs. Bad input is reported in plain language instead of producing a corrupt download, and nothing leaves the browser.

What this tool does

The details that matter when you use Base64 to Image for real work.

  • Data URL or raw Base64

    Paste the full data:image/...;base64,... string or only the encoded payload; both are decoded and the type is detected from the bytes.

  • Six image formats detected

    PNG, JPEG, GIF, WebP, BMP and SVG are recognised by their file signatures, so the download gets the right extension automatically.

  • Whitespace and Base64url tolerant

    Line-wrapped logs, spaces and the URL-safe - and _ characters are normalised before decoding, avoiding most copy-paste errors.

  • Preview before downloading

    The decoded image is rendered at its real aspect ratio, with the detected media type and decoded byte size shown underneath.

  • Decoding stays in the tab

    The string is decoded with atob and turned into a local Blob. It is never uploaded, stored or forwarded to another service.

How to use Base64 to Image

No account, no installation — the whole job happens in this browser tab.
  1. 01

    Paste the Base64 text

    Drop in a complete data URL or the raw Base64 payload, including any surrounding line breaks; whitespace is ignored.

  2. 02

    Press Decode image

    The browser decodes the string locally and checks the first bytes to identify the actual image format.

  3. 03

    Check the preview and size

    Confirm the picture looks right and note the detected media type and decoded size before saving it.

  4. 04

    Download the image

    Download the decoded file with the detected extension, then reset the form to decode another string.

How this tool works

Works with
BASE64 → IMAGE
Processing
Client-side, in your browser. Nothing is uploaded.
Maximum size
Up to about 40 MB of Base64 text
Requirements
Chrome, Edge, Firefox or Safari on desktop or mobile

Limitations worth knowing

  • Input text is limited to about 40 MB, which keeps the decoded copy inside a normal browser tab's memory budget.
  • Only PNG, JPEG, GIF, WebP, BMP and SVG signatures are recognised; other formats such as AVIF or ICO are rejected.
  • The byte check confirms the container format, not that every pixel decodes or that the image is trustworthy.

Privacy and file handling

The Base64 text is decoded in memory with the browser's atob function and turned into a local Blob for preview and download. Nothing is uploaded, saved or logged, and closing the page discards the input and the decoded image.

Read the full privacy policy

Base64 to Image FAQ

Short, direct answers to the questions people ask before using this tool.
How can I tell whether a string is Base64 image data?
A data URL begins with data:image/ followed by the format and ;base64,. Raw Base64 looks like a long run of letters, digits, +, / and = characters, and the first characters often match a known format signature such as iVBORw0KGgo for PNG.
What if the Base64 string is truncated or missing characters?
The decoder rejects strings whose length is invalid or whose bytes are not a recognised image, and the message explains that the text may be incomplete. Compare the character count with the source system; one missing character breaks the whole payload.
Does this tool verify that the image is safe to open?
It checks the file signature only, not the contents. The image is rendered in the browser like any other local file, but you should still treat Base64 from an untrusted source with the same caution as a downloaded image.
Why was my GIF or SVG saved with a different extension?
The extension follows the bytes that were decoded, not the label in the original text. If the source was genuinely a PNG payload pasted under an SVG data URL prefix, the saved file is a PNG.
Can I decode very large Base64 strings in the browser?
There is a limit of about 40 MB of input text, because decoding creates a second in-memory copy. Longer payloads are rejected with a clear message; decode them with a command-line tool instead.
Is the Base64 data uploaded to a server?
No. Decoding, format detection, previewing and downloading all happen in the browser tab. The string is never sent to FormatFlow or any third party and is discarded when the page is closed.
Does the decoded image keep its original metadata?
Yes, the decoded bytes are written out exactly as received, including EXIF or other embedded metadata. This tool neither adds nor strips metadata during decoding.

Background reading

Format guides that explain the trade-offs behind Base64 to Image.